A little practice... sometimes I like to draw on a small sheet of paper or one that is different from the usual size I work with... varying the format helps me improvise and let myself go with the strokes and shapes in such small formats that I later like to stick them in some space in my sketchbook to fill in and decorate the sheets I've already worked on.
Tell me which one was your favorite?
Do you decorate your sketchbooks with loose sheets or improvised sketches?